We’re awash in hyped claims made about the health impacts of countless foods and supplements. Determining which claims are backed by credible evidence isn’t always easy – contradiction is more common than clarity. A new review of “controversial and hyped” foods conducted by a team of researchers from the American College of Cardiology (the second in a series) attempts to inject some clarity by evaluating health claims against an array of research, with particular focus on heart health.
The review divides foods into three categories: Evidence of harm; Lacking in evidence of harm or benefit; and Evidence of benefit. For each food, the team evaluated the research and concluded with “bottom line” recommendations guided by the evidence.
In the “Evidence of harm” category, added sugars are unsurprisingly at the top of the list. “Added sugars promote atherogenesis [a disorder in which plaques form in artery walls] and increase cardiovascular disease (CVD) risk,” the review reports.
The evidence particularly points to the dangers of high fructose corn syrup (HFCS), which, despite claims by sugar industry lobbyists, does not affect the body in exactly the same way as other forms of sugar. Quoting from the paper: “Although sucrose and HFCS are now believed to be metabolically equivalent, their fructose and glucose moieties [chemical reactions] are not. Fructose uptake by the liver is unregulated and induces greater hepatic lipogenesis [process involved in storing energy as fat] than does glucose.”
The researchers recommend strictly limiting consumption of added sugars, especially sugary sodas, fruit drinks and sports drinks that account for half of our added-sugar intake: “Individuals should limit added sugar to less than 10% of calories, and preferably less than 100 calories daily for women and less than 150 calories daily for men.”
Energy drinks also rank high on the evidence-of-harm list for a slew of health badness, including “increased blood pressure, platelet aggregation, and arrhythmia risk.”
Dairy products sit prominently in the “Lacking in evidence of harm or benefit” category. While they’re often high in saturated fat, they’re also high in vitamins, minerals and high-quality protein. “It appears that there is no clear consensus in the published data or among experts on the effects of dairy products on CVD,” the review notes.
Fermented foods, including yogurt and kimchi, also appear in the lacking-evidence category, with research starting to show potential benefits of these gut-bacteria boosting foods. In general, however, the science is still too murky to support recommending them for heart health, although there’s also no evidence of harm.
The “Evidence of benefit” category is the biggest, featuring legumes, coffee, tea, omega-3 fatty acids, mushrooms and moderate alcohol consumption.
Coffee, the recent star of several studies showing health benefits, gets ample coverage here as well, with the conclusion that drinking a little each day is a great idea for overall health as long as it’s not loaded with sugar. “Moderate, habitual coffee consumption reduces risk for stroke, diabetes, premature death and digestive diseases,” the review confirms.
Tea also earns high marks, with strong evidence that it “improves artery health, reverses blood vessel dysfunction and reduces cholesterol.”
Omega-3 fatty acids from both plant and marine sources receive a favorable nod for “reducing CVD risk and improving lipid profiles,” but omega-3s from fish provide the clearest benefits (with the caveat that eating fish lower on the food chain is recommended to avoid ingesting too much mercury).
Mushrooms and legumes are both recommended as diet additions for being high in antioxidants and heart-healthy fiber. Although research to-date hasn't found strong heart health benefits from eating mushrooms, they "may be associated with improvement in inflammatory and antioxidative pathways and may have beneficial effects on known CVD comorbid risk factors."
Alcohol is the most controversial item in the review. The researchers say that while credible research shows upsides of moderate consumption (“vasodilatory, antiplatelet and anti-inflammatory properties”), the negatives may overshadow the benefits. “It is not recommended that individuals initiate alcohol consumption for health benefit, and for those already drinking, consumption should be limited to recommended amounts and preferably consumed with meals,” the researchers add in a cautionary footnote.
The research review, part 2 in a series, was published in the Journal of the American College of Cardiology.
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